I am planning to insulate my basement and rim joists with rigid/extruded polystyrene. I just found out about the foil-faced variety and was wondering if there is an advantage/disadvantage to using one over the other. Any help would be appreciated. Thanks.
Most foil faced foam boards are iso-cyanurate foam which will have a slightly higher R-value per inch than extruded poly-styrenes. There are some foil faced boards out there that are expanded poly-styrenes. This is the bead board that looks like cheap beer cooler foam. They are generally cheaper, lower performance materials. Whatever you use, foaming it in place with a low ex foam is a good idea.